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really strange hop situation on 1006475
by Marco Moock 23 Jul '25

23 Jul '25

Hello! Probe 1006475 has really interesting results: RESOLVED tr.dorfdsl.de TO 2a01:170:118f:30::100 STARTED QUERY AT 2025/07/23 14:52:56 UTC Fetching Measurement: 119451691 Traceroute from 2405:8d40:48d9:592f:10b8:22ff:fe88:a416 to 2a01:170:118f:30::100 (2a01:170:118f:30::100): 1 fd8d:b030:165f::1 8.901ms 0.79ms 0.762ms 2 tr.dorfdsl.de (2a01:170:118f:30::100) 268.925ms 262.384ms 262.513ms This cannot be true as my system is far away. I also receive that packet, so it is not a simulation etc. This is the situation from the other direction: m@tr:~$ sudo traceroute -I 2405:8d40:48d9:592f:10b8:22ff:fe88:a416 traceroute to 2405:8d40:48d9:592f:10b8:22ff:fe88:a416 (2405:8d40:48d9:592f:10b8:22ff:fe88:a416), 30 hops max, 80 byte packets 1 2a01:170:118f:30::1 (2a01:170:118f:30::1) 1.164 ms 2.235 ms 2.309 ms 2 2a01:170:0:10::1 (2a01:170:0:10::1) 10.751 ms 10.853 ms 10.816 ms 3 * * * 4 * * * 5 * * * 6 ffm-bb1-v6.ip.twelve99.net (2001:2034:1:6b::1) 10.444 ms 11.857 ms 11.418 ms 7 mei-b5-v6.ip.twelve99.net (2001:2034:0:15a::1) 26.477 ms 41.573 ms 41.224 ms 8 sng-b7-v6.ip.twelve99.net (2001:2034:0:14::1) 197.873 ms 197.940 ms 196.175 ms 9 * * * 10 ditona-ic-388046.ip.twelve99-cust.net (2001:2035:0:28f0::2) 194.862 ms 194.751 ms 194.879 ms 11 2405:8d40:2:103b::3 (2405:8d40:2:103b::3) 230.238 ms 230.303 ms 230.253 ms 12 2405:8d40:0:1002::2 (2405:8d40:0:1002::2) 222.359 ms 222.388 ms 222.404 ms 13 2405:8d40:3:1004::3 (2405:8d40:3:1004::3) 256.477 ms 248.020 ms 247.930 ms 14 2405:8d40:103:1013::3 (2405:8d40:103:1013::3) 242.521 ms 244.766 ms 243.801 ms 15 2405:8d40:a38:20b3::4d (2405:8d40:a38:20b3::4d) 243.622 ms 244.194 ms 244.200 ms 16 2405:8d40:48d9:592f:569:347b:29b8:4da3 (2405:8d40:48d9:592f:569:347b:29b8:4da3) 261.501 ms 271.957 ms 275.285 ms 17 2405:8d40:48d9:592f:10b8:22ff:fe88:a416 (2405:8d40:48d9:592f:10b8:22ff:fe88:a416) 255.513 ms 249.852 ms 248.217 ms m@tr:~$ Does anyone have a clue what is going on? Traffic manipulation at the remote ISP? -- Gruß Marco Send unsolicited bulk mail to 1753282214muell(a)stinkedores.dorfdsl.de

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Offset of NTP measurement
by Marco Davids (SIDN) 23 Jul '25

23 Jul '25

I noticed a discrepancy between the output of my own tool and RIPE Atlas. My tool reports the offset as a negative value, while RIPE Atlas shows a positive one. For example: https://atlas.ripe.net/measurements/115803954/results Any thoughts? -- Marco

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Possible Corner Case Bug in RIPE Atlas NTP Measurement
by Marco Davids 22 Jul '25

22 Jul '25

Dear RIPE Atlas team, I believe we may have discovered a corner case bug in the way RIPE Atlas handles NTP measurements. The issue surfaced during experiments with my NTP simulator — a small tool that mimics an NTP server and allows for controlled manipulation of its behavior. In one particular scenario, the simulator randomly varies the poll value in each response. While this doesn’t occur frequently in real-world implementations, it is technically valid behavior. It appears, however, that either the probes or the measurement system itself do not expect the poll value to change across responses. When initiating a measurement with the default setting of 3 packets, and each response has a different poll value, the result is that the measurement ends up reporting nothing. I first described this on the RIPE Atlas mailing list: https://mailman.ripe.net/archives/list/ripe-atlas@ripe.net/thread/33KNP7KPX… A detailed analysis can be found here: https://mailman.ripe.net/archives/list/ripe-atlas@ripe.net/message/OSRNUJ2Y… The NTP simulator is publicly reachable at: ntp1.testdns.nl I'd appreciate it if you could take a look. Thank you in advance for your time and consideration! Kind regards, -- Marco Davids SIDN Labs

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Re: Atlas probes not reporting NTP results on ntp0.testdns.nl ?
by Marco Davids 22 Jul '25

22 Jul '25

Hi Joachim, Thanks again for your work and the promising findings! I’ve updated the settings of the NTP simulator (now running at ntp1.testdns.nl) to keep the poll value fixed, and I’ve created a new measurement with 50 probes, each sending 10 packets per interval: https://atlas.ripe.net/measurements/118724341 And indeed — things already look a lot better! So... did we just find a bug? Best, -- Marco -------- Original Message -------- *Subject: *[atlas] Re: Atlas probes not reporting NTP results on ntp0.testdns.nl ? *From: *Joachim Kroß *To: *"Marco Davids (SIDN)" , ripe-atlas(a)ripe.net *Date: *Thu, 17 Jul 2025 15:30:35 +0200 > When multiple packets are sent per sample (default is to send three), > those are currently sent back to back. I.e., unless there is packet > loss, the second and third request are sent as soon as the response to > the previous request has been received. As consequence, the values of > the majority of fields in the responses are typically the same, e.g., > ref-id, poll, precision, stratum, version, mode, even ref-ts. As such, > they are at the top level of the JSON object. And the "result" structure > only has the fields that vary between the packets, i.e., the timestamps > related to the actual packet transmissions (and derived values). > > With the explicitly misbehaving server, however, some of the fields that > would typically not change between back-to-back responses, or rather > rarely only, _do_ change from one response to the next. E.g., the poll > and precision fields. In those cases, there still is an entry at the top > level of the JSON object, I guess perhaps derived from the first packet. > But then, the result structure would additionally have entries for those > types of fields where the value differs from the one at the top level.

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Atlas probes not reporting NTP results on ntp0.testdns.nl ?
by Marco Davids (SIDN) 18 Jul '25

18 Jul '25

Dear list, If anyone knows, or is able to figure out, why most (but not all) Atlas probes don’t report results for NTP measurements to ntp0.testdns.nl, I’d appreciate your insights. Examples: https://atlas.ripe.net/measurements/116922622/ https://atlas.ripe.net/measurements/116946257/ https://atlas.ripe.net/measurements/116830921/ Ping works: https://atlas.ripe.net/measurements/116921717/ Thanks in advance. -- Marco

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Re: Atlas probes not reporting NTP results on ntp0.testdns.nl ?
by Marco Davids (SIDN) 17 Jul '25

17 Jul '25

Hi Joachim, Thank you for looking into this! On Thu, 17 Jul 2025 15:30:35 +0200 Joachim Kroß wrote: > It seems the explicitly misbehaving server has been replaced by a more > sane one (albeit apparently not synchronized) Oh, yes that's correct - sorry for that. I started doing some tests with an NTPv5 enabled Chrony server. The NTP simulator is still available on another server though, albeit IPv6 only (because such VM's are so much cheaper): ntp1.testdns.nl. For those interested; my simple NTP simulator is here: https://github.com/mdavids/ntptools/tree/main/go/fake-ntp-server A version that allows to simulate jitter and clock drift is here: https://github.com/mdavids/ntptools/tree/main/go/fake-ntp-server-2 Just a few simple experiments, mostly the result of a bit of vibe coding. -- Marco

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Asking for credits for a university project
by Serban Orza 16 Jul '25

16 Jul '25

Hello, Atlas community! I am Serban Orza, a second-year Computer Science student at Delft University of Technology. Together with another 4 students, we are working on an open-source project that measures the accuracy and reliability of NTP servers. We already implemented the basics, but we would like to integrate RIPE Atlas to have a global perspective and to avoid the bias of a single measurement point. We would appreciate it a lot if somebody could provide us with some RIPE API credits to perform measurements and analyze the reachability of NTP servers. My account at RIPE NCC is on this email: orza(a)student.tudelft.nl Thank you! Serban

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sw-probe reducing syslog messages
by Hans Mayer 14 Jul '25

14 Jul '25

Dear All, I am running the package ripe-atlas 1.5-3 on Debian 12 bookworm with probe id 1010735. Is there a way to reduce the syslog messages for really necessary events like errors ? Kind regards Hans --

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software probe disconnected: REGINIT exit with error
by Marek Küthe 09 Jul '25

09 Jul '25

Hello, For a few hours now, my two software probes (#1008711 and #1008669) are no longer connected. I have attached the log. I build the software probe myself [1] and use a somewhat hardened systemd unit [2]. Does anyone know what I could do? Greetings Marek Küthe [1] https://codeberg.org/mark22k/dn42-router/src/commit/ae9b7cc8c36a7cb0dd9ce8d… [2] https://codeberg.org/mark22k/dn42-router/src/commit/ae9b7cc8c36a7cb0dd9ce8d… -- Marek Küthe m.k(a)mk16.de er/ihm he/him

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Location quantisation?
by Ray Bellis 08 Jul '25

08 Jul '25

In an effort to find and report probes with incorrect geolocation, I'm rather curious to find out what's special about a lake just west of Wichita (Kansas) that results in it having 11 probes in the middle of it? I suspect some sort of very coarse location quantisation, yet the probes there are not just distributed all over the US, but I also see a probe from Madrid and another from near Ljubljana. cheers, Ray

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Probe areas
by Yohan Prod'homme 07 Jul '25

07 Jul '25

Hello, When you start a measurement, you can specify an area to chose probes from. These areas are like "West", "North-Central", "South-East"... What do they corresponds to? If I use the "West" area, this is the west of what? Of the europe? Because "west of the world" barely makes any sense to me, and I can't find any documentation about these areas. I feel like I'm missing something obvious, so I'd be grateful if someone can enlighten me :) Thanks, Yohan

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Probe down ?
by Colin Johnston 30 Jun '25

30 Jun '25

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traceroute with specific udp target port
by julien.piccaluga 25 Jun '25

25 Jun '25

Hello, I’m developing a Proof of Location project and have a use case requiring a traceroute on a specific UDP port. It appears that traceroute only supports selecting a target port for TCP. Are there any undocumented or lesser-known methods to achieve this with UDP? Regards Julien Piccaluga Mobile: +41 (0) 78 832 36 20 Envoyé avec un e-mail sécurisé [Proton Mail](https://proton.me/mail/home).

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Probe location API
by Ray Bellis 25 Jun '25

25 Jun '25

My RIPE visualiser for the DNS root system has previously been using this endpoint, that now returns an error: https://atlas.ripe.net/api/v2/cartography/locations Is there another I can use in its place with the same output? thanks, Ray

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RIPE Atlas measurements broken since yesterday
by Lucas Rolff 24 Jun '25

24 Jun '25

Hello, It seems like creating new measurements through RIPE Atlas has been broken since yesterday afternoon, while the given measurement is created, it will simply return "Error fetching data", regardless of how long waits. e.g. a traceroute towards 8.8.8.8: https://atlas.ripe.net/measurements/111806687/overview Is RIPE aware of this issue? And any possible ETA when it will work again? - Lucas Rolff

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Request for RIPE Atlas Credits for Geo-Staking Research
by julien.piccaluga 17 Jun '25

17 Jun '25

Hello, I’m currently working on a project related to proof of location for blockchain Proof-of-Stake node decentralization. To support my testing, I would like to run a series of measurements using the RIPE Atlas platform. If anyone has spare credits and would be willing to share, I’d greatly appreciate your support. Thank you in advance for your generosity. Best regards, Julien Piccaluga Mobile: +41 (0) 78 832 36 20 Envoyé avec un e-mail sécurisé [Proton Mail](https://proton.me/mail/home).

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Request for RIPE Atlas Credits for Oceanic Connectivity Project
by Andrew 08 Jun '25

08 Jun '25

Him I’m Andrew and I'm currently working on a project aiming to test and analyze connectivity across the Atlantic and Pacific Oceans. The goal is to measure latency, reliability, and routing performance to better understand intercontinental connectivity and network behavior. To achieve a comprehensive perspective, we're planning extensive measurements using RIPE Atlas probes. However, we're limited by available credits. If anyone could provide RIPE Atlas credits to support this effort, it would be greatly appreciated. My RIPE NCC account email is: andrew(a)izongrp.com Thank you Andrew

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eperd segaults on software probe?
by Alexander Bochmann 07 Jun '25

07 Jun '25

Hi, on this one software probe I run, I've noticed a bunch of segfaults in eperd between May 19 and May 21: > May 19 11:23:51 kernel: eperd[1705]: segfault at 0 ip 00007a7e28e95ace sp 00007ffdaa698030 error 4 in libc.so.6[7a7e28e45000+155000] likely on CPU 1 (core 1, socket 0) > May 19 13:23:50 kernel: eperd[2119167]: segfault at 0 ip 0000793ee0becace sp 00007ffc83ca3bd0 error 4 in libc.so.6[793ee0b9c000+155000] likely on CPU 1 (core 1, socket 0) > May 19 13:53:52 kernel: eperd[2168145]: segfault at 0 ip 000070f2b71ecace sp 00007fff868d06d0 error 4 in libc.so.6[70f2b719c000+155000] likely on CPU 1 (core 1, socket 0) > [..] > May 21 07:53:55 kernel: eperd[3181618]: segfault at 0 ip 00007dfe4bc95ace sp 00007fffeaf5b420 error 4 in libc.so.6[7dfe4bc45000+155000] likely on CPU 1 (core 1, socket 0) > May 21 08:54:03 kernel: eperd[3218383]: segfault at 0 ip 00007dba7970cace sp 00007fff1d145490 error 4 in libc.so.6[7dba796bc000+155000] likely on CPU 1 (core 1, socket 0) > May 21 09:24:04 kernel: eperd[3243867]: segfault at 0 ip 000076d0a8becace sp 00007fff2ffb2b20 error 4 in libc.so.6[76d0a8b9c000+155000] likely on CPU 1 (core 1, socket 0) Software probe version is 5110 on Debian 12. I haven't found anything similar before or after. Coredumps are not enabled on that system, and I don't notice anything unusual in the service logs (except that eperd has been restarted), so that's pretty much the information I have... Has anyone else seen something like that? Alex.

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Best way to download bulk data older than a month?
by Vasileios Giotsas 02 Jun '25

02 Jun '25

I'm trying to download the RIPE Atlas traceroutes for a day that is older than one month. Given that the FTP repository publishes only results from the last month, I need to use the API. So, what I'm doing is to list of measurement IDs for a given data and then for each ID I do a GET for the results of that ID. The code is here: https://github.com/vgiotsas/RIPEAtlas_Queries/blob/main/download_atlas_trac… However, often some downloads time out and when I'm trying to resume it using the Range header it seems that the API doesn't support it and the download starts over until it fails again halfway through the download. Is there a better way to do such bulk downloads? Or at least to resume failed downloads? Thanks!

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Anchor time sources
by Tim Chown 27 May '25

27 May '25

Hi, I assume the anchor nodes take their time via NTP and a general NTP pool? Have there been studies of time drift on anchors? Is there a way to configure a specific set of NTP sources? Thanks, Tim

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Atlas reported uptime vs OS reported uptime
by Alexander Männel 26 May '25

26 May '25

Hi atlas folks, is there a way to get the operating system uptime of a probe? The reason I'm wondering is that I want to differentiate a shut down probe (i.e. power outage, operator reasons) from a disconnected probe (i.e. Internet connectivity lost). Depending on the goal of a measurement these two cases should be considered differently. The one way I think this is currently possible is to look for results that the probe has uploaded from its local buffer after it has regained network connectivity. In case of a disconnected probe, there will be measurement results during the outage but not if the probe was fully turned off. This approach is however a bit hacky and requires you to query the event log and align that with the measurement results. Depending on how often your measurement runs, you might have to query data from the built-ins as well. Of course you can always try to look at probes from the same region/AS and see if they faced outages, but this requires a lot of additional data to be queried and will not be 100% accurate. I understand that this probably is only relevant for a subset of all probes, but also collecting the uptime as tracked by the OS would be a simple fix to easily differenciate between different disconnect reasons. Regards, Alexander Männel -- Alexander Männel TU Dresden, Chair of Distributed and Networked Systems https://tu-dresden.de/cs/netd

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Ripe Probes clock update
by Giovane C. M. Moura 12 May '25

12 May '25

Hi Atlas folks, I was wondering if there is an update on how Atlas probes sync their clocks from the article from 10 years ago[0]. * Anchors: `pool.ntp.org` * v1: fallback mechanism using HTTP * v2 : ntpclient (but which ntp servers?) * v3: opentpd (but which ntp servers)? What about newer probes version? v4? v5? vms? Thanks, /giovane [0] https://labs.ripe.net/author/philip_homburg/ntp-measurements-with-ripe-atla…

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Atlas UI update - New Internet Maps
by Stephen Suess 01 May '25

01 May '25

Hello Atlas Community, We have just released an update to the UI that completely reworks the Internet Maps section: Root Name Server Instances & RTT to well-known destinations Performance: many times faster than previous maps Sharable URLs with all params Clickable legend tags to filter probe markers Probes on maps are searchable by ID, ASN, Country, IP, Prefix Time travel up to 30 days in the past You can find these maps here: https://atlas.ripe.net/maps/ Over the next couple of months we plan to bring many of the performance improvements of these maps to other areas of Atlas as well as refining and adding to the Internet Maps collection. And as always, we hope you find these changes useful and we welcome your feedback. Kind regards, Stephen Atlas UI

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RIPE Atlas API rate limits
by Huseyn Gambarov 30 Apr '25

30 Apr '25

Hello. While looking for the rate limits defined for the RIPE Atlas API, I found the mail sent by Robert Kisteleki two years ago saying: > The measurement API in particular will impose a limit of 150 queries/second (if done over multiple connections) Can you tell me please, if the requests sent to the Streaming API are also considered in this limit? Thank you. Original mail: https://mailman.ripe.net/archives/list/ripe-atlas@ripe.net/thread/7K4JC7ZZN… With regards, Huseyn Gambarov Research Assistant PhD Student in Computer Science Case Western Reserve University

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bulk-email.ripe.net
by Marco Moock 29 Apr '25

29 Apr '25

Hello! Some mails regarding RIPE atlas are being sent via bulk-email.ripe.net. Is there a reason RIPE uses that 3rd party (IPv4-only) service instead of its own infrastructure? -- Gruß Marco

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